Folks, if you've recently upgraded or renewed your annual club membership but it's still not active, please reach out to the BOD or a moderator. The PayPal system has a slight bug which it doesn't allow it to activate the account on it's own.
Ice Probes are only good for a max of 10-15 gallons and even then it's only a 1-2 degree pull down. On a 46 gallon you're looking at 4-5 of them, and at $150 each with the controller, plus shipping your looking at a cost of at least $600. That would buy you a nice sized chiller for the tank.